Work holding mechanism



Aug. 19, 1947. H. K, Hacia-:R 2,426,095

woRK HOLDING MECHANISM Filed Jan. 8, 1944 2 sheets-sheet 1 2 -h l I 13g'l /Nx/E/s/To: im@ Z, www www ik,

@ *W WMW' All@ 19, 1947 H. K. HECKER 2,426,095l

WORK HOLDING MECHANISM ,Filed Jan. 8, 1944 2 Sheets-Sheet 2 4 444495 I426 27 Pi f i'W/z;

Patented ug. 19, 1947 UNITED STATES PATENT OFFICE 16 Claims.

This invention relates to work holding mechanisms, particularlymechanisms for non-revolubly holding bar stock in position to beoperated upon by various tools. The invention has for its principalobjects to devise a powerful and easily operable, quick engageable anddisengageable bar stock gripping or clamping mechanism; to provide forquickly and easily positioning the bar stock for engagement by thegripping mechanism; to provide a nal accurate positioning of the barstock in the gripping mechanism; to provide ia bar roll-off surface uponwhich the bar stock is deposited when released by the grippingmechanism; to provide for movement of one of the jaws of the grippingmechanism below the bar roll-off surface when said mechanism is opened;to provide fluid actuated means for operating the movable gripping jaw;to provide for adjusting the gripping mechanism for various sizes andshapes of bar stock; to provide for varying the clamping pressure of thegripping mechanism; to provide a releasable stop for holding the barstock on the roll-oil surface; and to provide for varying the height andangle of the roll-off surface. The invention consists in the workholding mechanism and in the parts and combinations and arrangements ofparts hereinafter described and claimed.

In the accompanying drawings, which form part of this specification andwherein like symbols refer to like parts wherever they occur,

Fig. 1 is a top plan view of a work holding mechanism embodying myinvention, the pivotal connections between the toggle joint and thecarriage and between the toggle joint and the movable jaw element ofsaid mechanism being shown in horizontal section,

Fig. 2 is a vertical cross-sectional view on the line 2--2 in Fig. l,

Fig. 3 is a similar view on the line 3-3 in Fig. 1,

Fig.. 4 is a View similar to Fig. 3, showing the work gripping mechanismin released position; and

Figs. 5 and 6 are views similar to Fig. 3 illustrating two modied formsof the invention on an enlarged scale and with certain parts omitted.

The work holding mechanism shown in Figs. 1 to 4, inclusive, of theaccompanying drawings, comprises a grip carriage or body I supported onrollers 2 for movement along spaced panallel horizontally disposed railsor runner bars 3, of circular cross-section, two of such supportingrollers operating on each rail and being grooved to fit the curved uppersurface thereof. The

carriage is also provided with a plurality of similar grooved hold-downrollers 2a, each disposed beneath a supporting roll 2 and cooperatingwith the curved lower surface of a rail 3. The carriage I is providedwith mechanism for gripping or clamping thereto bar stock 4 of circularor other cross-section. Said mechanism comprises two relatively movableclamp blocks or jaws 5 and S that have their opposing ends grooved togrip opposite sides of said bar stock. The clamp block 5, whichconstitutes the stationary jaw element of the gripping mechanism, isremovably mounted in a, housing I rigid with the top of the carriage Iwith the grooved bar stock engaging end of said block projectinghorizontally from one end of said housing. The stationary clamp block 5is adjusted in the housing 'I for bar stock of different diameterspreferably by means of a screw 8 which is threaded through the closedend 44 of said housing in abutting relation to the inner or rear end 44aof said block, said screw being locked in the desired position ofadjustment by means of a lock nut 9.

The other clamp block or jaw element 6 of the above bar stock grippingmechanism is mounted in a housing I0 for movement therewith towards andaway from the stationary clamp block or jaw element 5 of said mechanism.The grooved bar stock engaging end of the clamp block 6 projects fromthe front end of the movable housing I0; and the rear end 45 of saidblock seats against an ladjusting screw II that is threaded through therear end 45a. of said housing and is locked thereto by means of a locknut I2. The supportl ing housing I0 for the clamp block 6 is preferablyformed integral with the free end portion of a rock arm or lever I3 thatis pivotally supported on a horizontal shaft I4 for Vertical swingingmovement towards and away from the stationary clamp block 5, said shaftbeing suitably supported in the end walls of the carriage I.

The supporting arm I3 for the clamp block 6 is actuated by means of atoggle joint comprising links I5 that are connected by ahorizontal pivotI6 to the carriage I and links I1 that are connected by a horizontalpivot I8 to the clamp block housing IB formed on the free end of saidarm. The other ends of the links I5 and Il are connected together by ahorizontal pivot i9, and the toggle joint is straightened to swing theclamp block 6 upwardly into operative position and broken to swing saidblock downwardly into inoperative position by means of a iluid operatedcylinder 20, which is pivotally supported, as at 2 I, in the carriage Ifor vertical swinging movement relative thereto and has a piston rod 22whose outer end is threaded into a clevis 23 that is pivotally connectedto the pivot I9 at the knee of said toggle joint. Air or other fluidpressure is supplied to the end of the cylinder 2| remote from thepiston rod 22 for straightening the toggle joint and to the end of saidcylinder adjacent to said piston rod for breaking said joint. By thisarrangement, the movable clamp block is swung upwardly into line withthe stationary clamp block 5 so as to clamp the bar stock 4 between theopposing ends of said blocks when the toggle is straightened; and saidmovable clamp block is swung away from said stationary clamp block torelease said bar stock when said toggle is broken. By adjusting theclamp block or jaw B. in its supporting lever I3, the pivots I5, I8 andI9 of the toggle joint may be moved closer to said straight line,thereby increasing the clamping pressure of said jaw.

As shown in the drawi-ngs, the carriage I is providedk along its topwith a bar stock roll-01T surface 24 which inclinesI downwardly from alevel just Vbelow the work engaging end of the stationaryv clamp block5- and across the path of movement of the movable clamp block 6 to oneside of the carriage; andthe movable clamp block supporti-ng housingswings upwardly above this roll-off Ysurface to` vengagethe `bar stock4` and below saidy surface when the bar stock is released. Thus, whenthe movable jaw S moves away from the stationary jaw 5 the bar stock isreleased and drops, upon the inclined roll-off surface 24, after whichsaid ymovable jaw swings downwardly beneath saidinclined roll-offsurface, thereby permitting said .bar stock to roll down such surfacetoy one Aside of the carriage I and onto a suitable discharge storagetable v25 located adjacent thereto. Located on the other side of -thecarriage is a bar stock. loading'table 26 having an upper work`supporting lsurf-ace ZTI that inclines downwardly towards andterminates in line with the working end of the stationary clamp block 5.Thus the bar stock 4; when positioned on the inclined roll-on surface 21-of the carriage loading table 26, will rolly downwardly thereon anddrop off the end thereofV infront Aof the working end of the stationary-block 5 and on-tothe inclined rollosurface 24 of the carriage I. Whenthe bar stock is thus deposited -on the inclined roll-off surface 24oppositethe working end of the stationary yclamp block 5, the movablecla-mp block E swings-upwardly through said surface into engagement withthe bar stock 4 which is lifted oli' the roll-off surfaceand accuratelycen-tered between the'working ends ofthe two-clamp blocks by theV-shaped Ibar eng-agingendsthereof. The above-arrangement provides ragrav-ity work feed anddischarg-e for the carriage-I However, if desired, the work piece may be-loaded on the 4carriage by sliding the-barstock 44 axially in front of the stationary jaw 5, by lowering ordropping saidstock in. front of said jaw or by sliding or rolling-saidstock upwardly lalong the roll-off vsurface 24.

The hereinbefore described work holding mechanism operates as follows.The bar stock 4 rollsdown the4 inclined'lo'adingv table V26v onone sidevofA the carriage I and: drops off the end thereof and isV deposited uponthe inclinedr'oll-oif surface 24 of said carriage where it is manuallyheld by the operator justin front Vof the V-shaped working endof thestationary jaw 5 of the bar gripping mechanism. 'The fluid cylinder 2|)Ais then actuated to straighten the toggle links I5 and I'I which swingthe movable jaw member 6 of the gripping mechanism upwardly above theinclined roll-oif surface 24 and into engagement with the side of thebar stock 4 that has just been deposited on said surface. Furtherstraightening of the toggle causes the bar stock 4 to be rigidly`clamped between the two jaws 5 and 6, the V-shaped ends of said jawscausing the bar stock to be lifted clear of the roll-oir surface 24 andto be accurately centered vertically relative thereto.

rlh'e carriage I is then moved along its supporting rails, to axiallyadvance and/or retract the bar stock, preferably by means of apower-driven pinion 28 that intermeshes with a longitudinal rack 29rigid with said carriage, after which the uid cylinder 2| is operated tobreak the toggle and swing the movable jaw 6 of the gripping mechanismbelow the roll-olf surface 24 of the carriage, whereupon the bar stockis deposited upon said roll-off surface and rolls oii the same onto thedis-charge storage table 25. As stated above, the fluid cylinder' 2U-for actuating the'.

' is similar to the work `gripping mechanism hereinbefore describedexcept that the support I'a,

which corresponds to the carriage I, is rigidly clamped, as at 39, toIthe two supporting rails 3a,.

and the'stationary jaw 5a of the gripping mechanism is mounted in thehousing 'Ia between a supporting plate in the bottom thereof and a coverplate 43u, for the top thereof. As shown in Fig. '5, the stationaiy jaw5a is adjusted vertically in the housing 'Ia'by `means of `screws 3|that are thre'adedinwardly through the bottom of said housing inabuttingY relation to the underside of the plate 4S therein; andV thecover plate 46a of said jaw is clamped downen the top of saidv jaw bymeans of screws 3|'cL` that exten-d downwardly through said' cover plateand are threaded into the side walls of. said housing. The construction`shown in Fig. 5 also includes a slightly different toggle operatingmechanismY for the movable jaw 9a. 'This mechanism comprises a link`I'Ia pivote'd, as at 18a, to the jaw supporting housing I'Ua of the rockarm |311 that is' pivotally vsupportedv on a horizontal pivot Manon thesupport Ita, a link 5o pivotally anchoredv as at |611, to the supportIa, a pivot ISa for pivotally connecting adjacent ends of said links,and a fluid'cylinder A2I|a pivotally supported, as at 2Ia, on said bodyand having 'a piston rod 22a connected at its outer end'` by means Vof ashackle 23a to the point of junction between said links. The operationof the-toggle operatedj'aw ofthe gripping mechanism .shown in Fig. 5`issubstantially that; shown` in Figs. 1 t0'4.

In? the construction shown'in. Fig; 5,' each' end of the stationaryybody; In has a stop lever 32 pivotedthereto; as :at 33, at the' lowerend' of its inclined roh-off surface'v 24a-for'vertical swingingmovementaboveandfbelow said: roll-oil surface,

only one `stop lever being shown; The stop lever 32 has the Ashapefofia" lbell 'crank with one arm extending below the ybody I'aandwiththe other arm extending toward the upper end of the rolloff surface 24athereof. The stop lever 32 is actuated by a push-and-pull rod 34 that ispivotally connected to the depending arm thereo-f; and, in the raisedposition of said lever, the free end 32a of the upper arm thereof isdisposed in the path of the bar stock l and prevents the same fromrolling down the roll-ofi' surface 26m and off the lower end thereof.When the stop lever 32 operated to swing the upper arm thereofdownwardly below the roll-off surface 2da, the bar stock is permitted toroll downwardly along the same onto a discharge table (not shown)similar Vto the discharge table 25 shown in Figs. l to 4f, inclusive.

The construction shown in 1Eig. 5 is also provided at each end with avertically disposed bar roll-off plate 35, which is .supported by thepivots 33 for vertical swinging movement relative to the body la, andhas a straight top edge 35a adapted to serve as a roll-off surface. Forbar stock l! of large diameter, the roll-off plate 35 is locked to thebody with its upper edge 35a below or flush with the roll-on surface 24aof the body la. For bar stock of relatively small diameter, the roll-offplate 35 is swung upwardly above the roll-off surface 2da of the body laso that its upper edge 35a constitutes a raised roll-off surface for thesmaller diameter bars. The roll-off plate t5 is looked in the desiredposi-tion of its swinging movement by means of a bolt 35 which extendsthrough angularly disposed elongated slots 3l and 38 formed in saidplate and the body la, respectively. Thus, the plate 35 may be raisedand lowered by sliding the bolt relative to the intersecting slots 31and 38, thereby causing said plate to move relative to the body la.

In the modification shown in Fig. 6, the pivotal jaw supporting memberlb of the bar stock gripping mechanism is pivotally supported, as at 39,in the carriage lb and is swung upwardly to bring the jaw 6b into linewith the stationary jaw 5b to grip the bar stock between said jaws bymeans of an edge cam [Si] that is mounted on a horizontal shaft 4lcarried by said carriage and has a cam surface 40a that cooperates withthe underside of a horizontal cam roller 2 journaled on the pivotal jawsupport. The cam 4B is swung upwardly to close the movable jaw 6b bymeans of a fluid operated cylinder Zeb that is pivotally supported, asat 2lb, in the carriage lb and has a piston rod 22h that is pivotallyconnected by a clevis 23h, to said cam. A coil tension spring 43 has oneend anchored to a pin 31 Xed to the carriage lb beneath the stationaryjaw 5b and has its other end secured to a lug i3 on the pivoted end ofthe jaw supporting member |3b, whereiby said spring operates to hold thecam roller 42 on the pivotal jaw supporting member against the camsurface lila of the edge cam 4B and to swing said member downwardly intojaw opening position when said cam is moved in-to inoperative positionby the fluid operated cylinder 2Gb. Obviously, the hereilnbeforedescribed work gripping mechanism admits of considerable modicationwithout departing from the invention. Therefore, I do not wish to belimited to the precise arrangements shown and described.

What I claim is:

1. A work holding mechanism comprising a body having a work supportingsurface,la stationary jaw located above said surface in position tolaterally engage one side of work thereon, and a jaw mounted in saidbody for movement upwardly above said surface into lateral engagementwith the opposite side of said work to immovably clamp the latterhorizontally between said jaws and downwardly beneath said surface torelease said work.

2. A work holding mechanism comprising a body having a supportingsurface, a stationary jaw mounted on said body above said surface inposition to laterally engage one side of a work piece thereon, and a jawmounted on said body for vertical swinging movement upwardly above saidsurface to substantially the level of said stationary jaw into lateralengagement with the opposite side of said work piece to immovably clampthe latter horizontally between said jaws and downwardly beneath saidsurface to release said work piece.

3. A holding mechanism for a work piece, said mechanism comprising abody having an inclined supporting surface, a stationary jaw locatedabove said inclined surface and positioned to laterally engage one sideof work piece deposited thereon and a jaw pivotally mounted in said bodyfor movement upwardly above said inclined surface and towards saidstationary jaw into lateral engagement with the opposite side of saidwork piece to lift the latter off said inclined surface and immovablyclamp it horizontally between said jaws and for movement away from saidstationary jaw to release said work piece and downwardly below saidinclined surface to permit; the released work piece to move downwardlythereon.

4. A work holding mechanism comprising a body having a work supportingsurface, a stationary jaw located above said surface in position tolaterally engage one side of work thereon, a jaw mounted in said bodyfor vertical swinging movement upwardly above said surface into lateralengagement with the opposite side of said work to immovably clamp thelatter horizontally between said jaws and downwardly beneath saidsurface to release said work, and means for actuating said movable jaw,said means being adjustable to vary the clamping pressure of saidmovable jaw.

5. A holding mechanism for bar stock of substantially circular section,said mechanism com- Y prising a body having an inclined bar stockrollonc surface, a stationary jaw located above said roll-01T surface, amember having an inclined bar stock roll-on surface adapted to depositthe bar stock on said roll-off surface in position to be laterallyengaged on one side by said stationary jaw, and a jaw mounted on saidbody for movement upwardly above said roll-off surface and.

towards said stationary jaw into lateral engagement with the oppositeside of said bar stock to immovably clamp the latter horizontallybetween said jaws and laterally away from said stationary jaw to releasesaid bar stock and downwardly entirely beneath said roll-off surface.

6. A work holding mechanism comprising a body having a work supportingsurface, a stationary jaw located above said surface in positio-n tolaterally engage one side of work thereon, a second jaw, and asupporting lever for said second jaw pivotally mounted in said body formoving said second jaw upwardly above said surface and laterally towardssaid stationary jaw into engagement with the opposite side of said workto immovably clamp the latter horizontally between said jaws andlaterally away from said stationary jaw to release said work anddownwardly below said surface.

7. A work holding mechanism comprising a body having two verticallyoffset work supporting surfaces inclined in the same direction, a fixedjaw located in the offset between said surfaces,

and a jaw `pivotally Vmounted on saidbodyfor vertical swinging movementupwardly above the lower surface into lateral engagement with workdropped thereon from the upper surface-to clamp said work horizontallybetween said jaws, Aand laterally away from said stationary jawto`release said work and downwardly 'beneath said lower surface. n Y

'8. -A work holding mechanism comprising a bod-y having an inclinedroll-01T surface, a Xed jaw locatedfabove said roll-olf surface-andadapted to engage one side of work deposited thereon, a jaw mounted insaid body for vertical'swingin'g movement upwardly above said roll-offsurface into engagement with the opposite side of said work to clamp thelatter between said jaws and downwardly below said surface to releasesaid work, and a stop movable above said inclined rolloir surface 'toVretain said work thereon. n

V9. The'co'mbination set forth in claim`8, wherein said roll-off surfacecomprises Ya, member mounted on said body for vertical adjustmentrelative thereto and means is provided for locking said member in-anyposition of its vertical movei merit.

lO. 'A work holding mechanism comprising a bo'd'y having an inclinedroll-'off surface, a 'Xed jaw located above said roll-o`ff surface andadapted`to engage on'e side of work depositedl thereon, a jaw'mount'edin' said body for vertical swinging movement upwardly above saidroll-off surface i-n'toI engagement with the opposite side of said workto clamp the latter between said jaws andk downwardly below said surface'to release said wo'i'k, a member-mounted on said body for verticalmovement relative thereto and constituting said' roll-off surface, andmeans for locking said member in any' position of lits verticalinovenieht.

11. A work holding mechanism comprising a body having a work supportingsurface, a stationary jaw located above said surface l and adapted tolateral-'ly' engage one side vof woll: deposited thereon, a jaw mountedin said body `for vertical swinging movement upwardly abovesaiclV workSupporting surface and towards said stal tfi-onary jaw into engagementwith the opposite side of said work to iinmovably clainpthe latterhorizontally between said jaws and downwardly below said vsurface torelease said work; and a toggle mechanism mounted on said support andcooperating with` said movable jaw to actua'te the same.

1-2; The vcombina-tion set forth in claim 11 wherein means is' providedfor adjusting saidV toggle' mechanism to varyv the pressure of saidmovable jaw on said work.

13. A- work holding mechanism lcomprising a body having a worksupporting surface, a stationary jaw located` above Said surface andadapted to laterally engage one side of work deposited thereon, a jawmounted in said body for vertical swinging movementupward'ly above saidwor-k supporting surface into engagement with the opposite side ofl saidwork to immovably clampA the latter horizontally between sai-d jaws anddownwardly below said surface to release said work, and a togglemechanism mounted on said support andcooperating with saidmovable jaw toactuate the same, said toggle mechanism comprising a pair oflinkspivotally secured together, the remote ends of said links beingpivotally lconnected 'one to saidjsupport vand Athe other to saidmovable jaw, and means mounted entirely on saidsupport cooperating withsaid links at their point ofnjunction for straightening and breakin-gIsaid toggle mechanism.

14. A work holding mechanism comprising a body having a work supportingsurface, a stationary jaw located above said surface and adapted tolaterally engage one side of work deposited thereon, a jaw mounted insaid body for vertical swinging movement upwardly above said worksupporting Vsurface into engagement with the opposite side of said workto immovably vclan'p the latter horizontally between said jaws anddownwardlyu'below said surface to release said work, a toggle mechanismmounted on said lsupport andv cooperatirigwith said movable jaw toactua-te the same, said toggle mechanism comprising a pair of links-pivo'tally secured together, the remote ends of said links beingp'ivcitally connected on'e to said support and the other to said movablejaw, a fluid pressure cylinder pivotally mounted on said body andcooperating with said links at their point of junction for straighteningand breaking said toggle mechanism, and means for adjusting said togglemechanism to vary the pressure of said movable jaw on said work. I

15. A work holding mechanism comprising a body with a stationary jaw, ajaw pivotally supported on said body for movement relative thereto toclamp work horizontally between said jaws, and means mounted on saidsupport for moving said pivotal jaw into work clamping position, said-ineans comprising a cam rotatably supported on said body, a cam rollercarried by said pivotal jaw and engageable byv said cam, and meanscarried by said body for actuating said Can.

1'6. A work holding mechanism comprising a body having a supportingsurface, a stationary jaw mounted on said body above said surface inposition to engage one side of a work piece thereon, and a jaw mountedon said body for vertical swinging movement upwardly above said surfaceto substantially the level of said stationary jaw into engagement withthe opposite side o'f said work piece to clamp the latter horizontallybetween said jaws and downwardly beneath said surface to release saidwork piece, an'd means mountedy on said body for moving Said jaw intowork clamping position, said means comprising ay cam mounted on saidbody, a roller movable with said movable jaw and engageable by said cam,fluid pressure operated means for actuating said cam, `and means forholding said roller in engagement with saidcam.

HARVARD K. HECKER.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,048,705 Kleirnan Dec. 3l, 19121,569,327 Linthwaite Jari-12, 1926 1,716,840 Stevenson June '111, 19291,922,980 Reis Aug. 15, i933 1,809,068 Roth June 9, 1931

